The present invention pertains to improvements in the field of wound suturing. More particularly, the invention relates to a moisture-curable adhesive closing strip for closing a wound on a patient.
When closing a wound, it is necessary to join and keep together the facing edges of the wound. If the separated skin sections are sewn, unesthetical scars may remain, and if they are stapled, such scars generally remain.
Cyanoacrylate-based adhesives have been suggested as an alternative to sutures. When a cyanoacrylate adhesive is employed, the separated skin sections are joined and the adhesive is applied on top of the joined sections under sterile conditions. The cyanoacrylate adhesive bonds to the skin and polymerizes so as to keep together the joined sections. Although cyanoacrylate adhesives successfully bind the skin, the use of such adhesives as suture replacements can be accompanied by occasional adhesion failure resulting in wound reopening which requires closure by sutures. Fear of wound reopening is one of the reasons physicians have been reluctant to use any adhesive including cyanoacrylate-based adhesives instead of sutures.
U.S. Pat. No. 5,254,132 proposes a method of treating suturable wounds by first suturing or stapling the wound and then joining the skin between sutures or staples with a cyanoacrylate adhesive. According to this method, the wound is sutured or stapled so that the sutures or staples are separated from each other by no more than about 1.2 centimeter and no less than about 0.6 centimeter. 2-Butylcyanoacrylate is then applied to the opposing and still separated skin sections between the sutures or staples in an amount sufficient so that upon polymerization the skin sections are joined; the application is conducted so that contact of the cyanoacrylate adhesive with the sutures or staples is avoided. The adjacent separated skin sections are thereafter contacted under conditions that permit the adhesive to polymerize so as to join the separated skin sections. Such a method is not only time-consuming and requires particular skill to practice, but also delays healing of the wound if cyanoacrylate adhesive penetrates in between the skin sections.
Surgical adhesive plasters for closing wounds are also known. These plasters generally do not have much tensile strength so that their use is limited to shallow wounds requiring little tension to close. Another major disadvantage resides in their permeability to water, causing the plaster to become unstuck upon contact with water or moisture and thereby preventing the wounded area from being washed.
U.S. Pat. No. 5,259,835 discloses a wound closure device that employs a porous bonding member adapted to receive a flowable moisture-curable surgical adhesive. The bonding member is positioned by a carrier member which is used to achieve initial apposition of the wound and which may later be removed. Since the adhesive flows into the bonding member and the latter serves as a matrix for the adhesive, the bonding member becomes rigid as the adhesive therein undergoes curing so that it looses flexibility. Part of the surgical adhesive also flows through the bonding member and may enter into the wound.
It is therefore an object of the present invention to overcome the above drawbacks and to provide a moisture-curable adhesive suture strip for closing wounds.
According to one aspect of the invention, there is provided a moisture-curable adhesive suture strip for closing a wound on a patient, comprising:
an elongated, flexible air-permeable backing member formed of a chemically inert material and having opposite ends, first and second surfaces facing away from one another and a length and width sufficient to secure facing edges of the wound in close juxtaposition to one another, the backing member comprising a first portion disposed between the ends and adapted to overlie the facing edges of the wound, and second and third portions disposed on either side of the first portion;
a moisture-curable surgical adhesive on at least part of the first surface of the backing member including the second and third portions thereof, for adhering at least the second and third portions of the backing member to the patient with the facing edges of the wound in close juxtaposition; and
a first removable protective member formed of a chemically inert material releasably secured to the backing member and covering the surgical adhesive.
After removal of the protective member to expose the adhesive and application of the backing strip with the exposed adhesive onto the patient to secure the facing edges of the wound in close juxtaposition, the adhesive upon curing together with the backing strip maintain the facing edges of the wound in close juxtaposition, without the cured adhesive adversely affecting the flexibility of the backing strip.
Applicant has found quite unexpectedly that by using a flexible and air-permeable backing member and applying on one surface of such a member a surgical adhesive, one obtains a suture strip which can be easily and rapidly applied onto the patient to secure the facing edges of the wound in close juxtaposition with one another, without the adhesive entering into the wound and delaying healing thereof. The adhesive upon curing together with the backing member maintain the facing edges of the wound in close juxtaposition, thereby preventing adhesion failure and reopening of the wound. Since the flexibility of the backing member is not adversely affected by the cured adhesive, the suture strip remains flexible and can thus follow movements of the skin. The backing member is of course air-permeable to enable the skin to breathe. Examples of suitable surgical adhesives which can be used include cyanoacrylates such as 2-n-butylcyanoacrylate and 2-octylcyanoacrylate. The curing time of 2-n-butylcyanoacrylate is about 30 seconds, whereas that of 2-octylcyanoacrylate is about 60 seconds. Preferably, the surgical adhesive comprises a cyanoacrylate in admixture with a stabilizing agent such as sulfurous acid.
The expression xe2x80x9cchemically inert materialxe2x80x9d as used herein refers to a material which does not react with the surgical adhesive to cause curing thereof during storage of the suture strip. Examples of suitable chemically inert material include polyethylene and tetrafluoroethylene. When the backing member is formed of polyethylene, use is preferably made of a low density polyethylene or a blend of low density polyethylene and high density polyethylene. The protective member, on the other hand, preferably comprises a film of high density polyethylene.
According to a preferred embodiment of the invention, a layer of surgical adhesive completely covers the first surface of the backing member. Preferably, the backing member comprises a canvas of chemically inert material having at the first surface cavities filled with the surgical adhesive to provide an anchoring of the backing member to the patient.
According to another preferred embodiment, a plurality of spaced-apart dots of surgical adhesive are provided only on the second and third portions of the backing member. Preferably, a pressure-sensitive adhesive is provided on the first surface of the backing member between the dots of surgical adhesive, the protective member covering the pressure-sensitive adhesive.
According to a further preferred embodiment, a plurality of spaced-apart strips of surgical adhesive are provided only on the second and third portions of the backing member, the strips of surgical adhesive extending transversely of the backing member. Preferably, a pressure-sensitive adhesive is provided on the first surface of the backing member between the strips of surgical adhesive, the protective member covering the pressure-sensitive adhesive.
Generally, the dots or strips of surgical adhesive define a total area representing from about 10 to about 50%, preferably from about 15 to about 30%, of the area defined by the first surface of the backing member.
According to yet another preferred embodiment, a finger-grip tab is detachably connected to the backing member at one of the ends thereof along a tear-line extending transversely of the backing member. Such a tab enables one to pull the backing member away from the protective member and thereby remove the latter to expose the adhesive on the backing member. After the suture strip has been applied onto the patient""s skin, the tab is torn away. Preferably, the protective member is substantially coextensive with the backing member along the length thereof and the tab, and extends beyond opposite side edges of the backing member and tab.
According to still a further preferred embodiment, a second removable protective member having a pressure-sensitive adhesive on one side thereof is releasably secured to the backing member and covers the second surface thereof, the backing member being disposed between the first and second protective members. Instead of using a second pressure-sensitive adhesive, it is also possible to removably attach the second protective member to the backing member by heat or pressure application. Examples of suitable pressure-sensitive adhesives which may be used include rubber or oil-based adhesives. The second protective member preferably comprises a film of low density polyethylene. Preferably, each of the first and second protective members extends beyond opposite end edges and opposite side edges of the backing member to define respective first and second end portions and first and second lateral portions. The first end portions and the first and second lateral portions of the first and second protective members face one another and are releasably bonded together by the pressure-sensitive adhesive or any other suitable method. The second end portion of the second protective member faces the second end portion of the first protective member and is partially free of adhesive so as to define with the second end portion of the first protective member a pair of finger-grip tabs.
The present invention also provides, in another aspect thereof, a moisture-curable adhesive suture strip comprising:
an elongated, flexible air-permeable backing member having opposite ends, first and second surfaces facing away from one another and a length and width sufficient to secure facing edges of the wound in close juxtaposition to one another, the backing member comprising a first portion disposed between the ends and adapted to overlie the facing edges of the wound, and second and third portions disposed on either side of the first portion;
a plurality of spaced-apart rupturable spherules secured to the first surface of the backing member and disposed on at least the second and third portions thereof, the spherules each comprising a rupturable membrane formed of a chemically inert material and encapsulating a flowable, moisture-curable surgical adhesive, and being adapted to release upon rupture of the membranes the surgical adhesive onto part of the first surface of the backing member including the second and third portions thereof;
a pressure-sensitive adhesive on the first surface of the backing member between the spherules for adhering at least the second and third portions of the backing member to the patient with the facing edges of the wound in close juxtaposition, prior to rupture of the spherules; and
a removable protective member releasably secured to the backing member and covering the spherules and the pressure-sensitive adhesive.
After removal of the protective member to expose the spherules and the pressure-sensitive adhesive, application of the backing member with the exposed spherules and pressure-sensitive adhesive onto the patient to secure the facing edges of said wound in close juxtaposition and application of pressure onto the second surface of the backing member to cause rupture of the spherules and release of the surgical adhesive therefrom, the surgical adhesive flows on part of the first surface of the backing member and upon curing forms discrete bonding sites strengthening the adhesion of at least the second and third portions of the backing member to the patient and cooperating with the backing member to maintain the facing edges of the wound in close juxtaposition without the cured adhesive adversely affecting the flexibility of the backing member.
The above suture strip featuring rupturable spherules comprising a rupturable membrane formed of a chemically inert material and encapsulating the surgical adhesive avoids having to use a backing member and a protective member formed of a chemically inert material. For example, the backing member can be formed of polyurethane or nylon. Use can also be made of a backing member comprising a web of fabric material. The protective member, on the other hand, can comprise a sheet of wax paper. However, a protective member comprising a film of high density polyethylene is preferred.
According to a preferred embodiment, the spherules are provided only on the second and third portions of the backing member.
According to another preferred embodiment, a portion of the first surface of the backing member surrounding each spherule is free of pressure-sensitive adhesive for receiving the surgical adhesive released from the spherule upon rupturing.
Instead of securing the spherules to the backing member, it is possible to secure the spherules to the protective member. The present invention therefore provides, in a further aspect thereof, a moisture-curable adhesive suture strip comprising:
an elongated, flexible air-permeable backing member having opposite ends, first and second surfaces facing away from one another and a length and width sufficient to secure facing edges of the wound in close juxtaposition to one another, the backing member comprising a first portion disposed between the ends and adapted to overlie the facing edges of the wound, and second and third portions disposed on either side of the first portion;
a pressure-sensitive adhesive on at least part of the first surface of the backing member including the second and third portions thereof, for adhering at least the second and third portions of the backing member to the patient with the facing edges of the wound in close juxtaposition;
a removable protective member releasably secured to the backing member and covering the pressure-sensitive adhesive, the protective member having first and second surfaces facing away from one another with the first surface facing the first surface of the backing member; and
a plurality of spaced-apart rupturable spherules disposed between the backing member and the protective member and secured to the first surface of the protective member, the spherules each comprising a rupturable membrane formed of a chemically inert material and encapsulating a flowable, moisture-curable surgical adhesive, and being disposed on the protective member at predetermined locations so as to release upon rupture of the membranes the surgical adhesive onto part of the first surface of the backing member including the second and third portions thereof.
After application of pressure onto the second surface of the backing member or protective member to cause rupture of the spherules and release of the surgical adhesive therefrom, removal of the protective member to expose the pressure-sensitive adhesive and the surgical adhesive released on part of the first surface of the backing member and application of the backing member with the exposed pressure-sensitive adhesive and surgical adhesive onto the patient to secure the facing edges of the wound in close juxtaposition, the surgical adhesive upon curing forms discrete bonding sites strengthening the adhesion of at least the second and third portions of the backing member to the patient and cooperating with the backing member to maintain the facing edges of the wound in close juxtaposition without the cured adhesive adversely affecting the flexibility of the backing member.
According to a preferred embodiment, the spherules are disposed on the protective member opposite only the second and third portions of the backing member.
According to another preferred embodiment, a portion of the first surface of the backing member opposite each spherule is free of pressure-sensitive adhesive for receiving the surgical adhesive released from the spherule upon rupturing.
According to yet another preferred embodiment, the spherules whether secured to the backing member or protective member have a diameter ranging from about 0.5 to about 3 mm, preferably from 1 to 2 mm. Generally, the spherules define a total area representing from about 10 to about 50%, preferably from about 15 to about 30%, of the area defined by the first surface of the backing member.